The present invention relates to a drive mechanism for vertical rolling mills and more particularly it relates to a drive mechanism for vertical rolling mills which itself is provided with a device for mounting a driven coupling on and dismounting it from the neck of a working roll.
A conventional vertical rolling mill uses as its drive mechanism a universal spindle such as those shown in FIG. 1. Thus, the torque from a motor 1 is transmitted to working rolls 5 through a speed reducer 2, bevel gear units 3 and universal spindles 4. The universal spindles 4 are connected to the drive and driven sides through upper and lower slipper couplings 6 and 7, respectively. At the time of roll exchange, an unillustrated pin associated with the slipper coupling 7 is removed to remove the slipper, thus cutting the connection between the roll 5 and the spindle 4, and then the shaft portion of the universal spindle 4 is pulled laterally as indicated by an arrow and held in that position, whereupon roll exchange is effected. In the figure, 8 designates a vertical rolling mill stand and 9 designates a roll stand.
In such vertical rolling mill with universal spindles, there has been the drawback that roll exchange involves very troublesome procedures, including removal of the pin and slipper and pulling of the universal spindle shaft portion, and requires much time and labor. Further, the slippers wear in a short time and there are many problems about their material and lubrication. Another drawback is that the wear of such slipper has to be contended with by the troublesome procedure of filling the resulting gap with a shim or shims and that the maintenance thereof is difficult.
On the other hand, as is disclosed in U.S. Pat. No. 3,670,587, there has been proposed a vertical rolling mill designed so that roll exchange is effected by moving two working rolls away from each other and then downwardly and pulling out the roll necks from the couplings of the drive mechanism. In this case, however, an elaborate device is required for sliding said working rolls laterally and moving them axially, and unless the couplings of the drive mechanism are fixed in position after the roll necks are pulled out, the subsequent procedure of inserting fresh roll necks into the couplings becomes very difficult. Therefore, it is necessary to provide a fixing device therefor.